The vehemence of workers over wages and other issues caught the company and union leaders off guard. When thousands of Boeing employees rejected a new labor contract, precipitating a strike that began on Friday, they were at odds not just with management but also with the leaders of their union, who backed the proposed deal.

The Boeing union strike follows a few years of strong gains for the labor movement. But labor’s leverage could narrow as the job market weakens in coming months.

At the heart of the Boeing strike that began Friday is a story about what happens when penny-pinching executives lose the plot and it falls to workers to get everyone back on track.